close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2109103

код для вставки
2,10%3
Patented Feb. 22, 1938
UNITED ‘STATES PATENT OFFICE
2,109,103
IGNITION TIMING CONTROL
Don Cole, Evanston, Ill., assignor to Bendix Prod
ucts Corporation, South Bend, Ind., a corpora
tion of Indiana
Application September 10, 1934, Serial No. 743,375
10 Claims.
(Cl. 123-117)
This invention relates to means for controlling
the load if the same speed is to be maintained,
the ignition of internal combustion engines, and
or the same load may be carried at a reduced
more particularly to a method of and means for
speed.
automatically regulating the time of ?ring the
5 spark in the combustion chamber of the engine in
To obtain the greatest el?ciency from the en
gine it is necessary to vary the time of igniting
accordance with variables such as manifold vac-‘
the charge so that the maximum power will be
exerted upon the piston near the beginning of
the power stroke. The rate of flame ‘propaga
uum, throttle opening, and speed of the engine.
It is known that the combustible mixture, in the
cylinder of an internal combustion engine does not
10 explode instantaneously, but that an interval of
time is required for the entire charge to become
ignited. This time lag depends upon the rate of
?ame propagation, which is a variable dependent
upon the density of the charge and the pressure
1 to which the charge is subjected, as well as other
factors. The rate of ?ame propagation becomes
more rapid as the density of the charge increases,
and also more rapid as the pressure of the charge
is increased.
20
To secure maximum efficiency from the engine
and also to obtain the greatest amount of power
from a given quantity of fuel it is necessary that
the spark which ignites the charge should occur
before the piston reaches the top dead center
25 position. The degree of advance should be suffi
cient to permit the entire charge to become fully
ignited shortly after the instant when the piston
reaches the top dead center position, on the com
pression stroke. In this manner the force of the
expanding gases will be exerted upon the face of
the piston in the most eifective manner. The
degree of spark advance to secure best results is
thus necessarily dependent upon the rate of flame
propagation.
35
If the spark occurs too early the charge will be
fully ignited before the piston reaches the top of
its stroke and the expanding gases will resist the
movement of the piston, resulting in loss of power
and rough running. If the spark occurs too late
the full force of the expanding gases will not be
exerted upon the piston at the beginning of the
power stroke and a decreased ef?ciency will result.
Since the time required for the propagation of
the ?ame in a charge of a given density remains
' practically constant, it follows that as the engine
is speeded up the degree of spark advance, meas
ured in degrees, must be increased vif the full
power of the expanding gases is to be exerted
upon the piston at the beginning of the power
stroke. In present-day automobiles, this is com
monly done automatically by a speed-responsive
mechanism known as the automatic spark ad
vance.
The power developed by the engine is a function
of the density of the charge admitted and also of
the speed of the engine. Thus with an increase
in the charge admitted to the cylinders the en
gine may carry a greater load at the same speed
or the same load at a higher speed. Likewise,
reducing the charge necessitates a reduction in
tion must therefore be taken into account, and
since this depends primarily upon the density of
the charge it is necessary to make suitable ad
justments for throttle setting, which is one of
the factors determining the density of the charge.
According to a preferred embodiment of this
invention I have therefore provided a novel con- ‘
nection between the throttle valve actuating
mechanism and the ignition timing system where
by the spark is advanced as the throttle valve is
moved toward the open position.
When the engine is running at idling speed or 20
comparatively slowly with the throttle valve
closed or nearly closed the pumping action of the
cylinders exerted on the carburetor will result in
a high vacuum in the intake manifold.
If now
the throttle is opened, either to increase the speed 25
of the engine or to enable the engine to carry an
increased load at the same speed, a greater charge
of air and fuel vapor will be supplied to each
cylinder per intake stroke and the negative pres
sure or vacuum existing in the intake-,manifold 30
will be destroyed. Under such conditions, it is
necessary to retard the spark to prevent back
?ring or pounding which would be detrimental
to the engine.
One of the important objects of this invention
is the provision of novel means whereby the spark
is automatically retarded when the negative pres
Cl
sure or vacuum in the induction passage posterior
to the throttle valve is destroyed.
Another object of this invention is to so control 40
the ignition of the charge in the combustion
chambers that the maximum power is obtained
from the fuel.
Having these and other objects in mind, one
embodiment of the invention comprises a novel
connecting linkage between the throttle valve and
the ignition system of an internal combustion
engine. In the embodiment shown, the spark is
advanced as the throttle valve moves from closed
to partially open position and is retarded as the 50
throttle valve is moved from a partially open to a
still greater open position.
In the illustrative accompanying drawing this
linkage is shown as a ?oating cylinder operably
connected with the timer of the ignition system,
with a piston therein operably connected with
the throttle valve. The cylinder is yieldingly
urged in one direction by a spring and is adapted
to be urged in the other direction by suction
transmitted to the cylinder through a duct com
2
2,109,103
municating with the intake manifold of the en
gine.
A further object of this invention is to produce
an automatic ignition regulating system of the
type described which is simple in operation and
which can be manufactured very inexpensively.
Other objects and advantages of the present in
vention will be more apparent from the following
detailed description and from the illustrative em
38, such movement being limited by a stop 52
carried by the cylinder.
The operation of the device, when the engine
is running at idling speed, is as follows. The
throttle valve I4 will be closed and the lever 42
will be in engagement with a stop member 50,
so that the piston 38 will be in the extreme right
hand position (as shown). A comparatively high
suction will exist in the manifold riser I0 and will
10 bodiments of the invention in the accompanying 1 be transmitted to the cylinder 28 through the duct 10
drawing which are intended merely for illustrative
48, holding the cylinder 28 to the left, maintaining
purposes and are not intended to de?ne the scope
the stop member 52 against the piston 38 by com
pressing the spring 46, and rotating the arm 32
in the counterclockwise direction from its extreme
of the invention, reference being had for that
purpose to the subjoined claims.
15
In the drawing:
Figure 1 is a diagrammatic view showing an
apparatus embodying the invention; and
Figure 2 is a chart showing the relation of en
gine speed to spark advance in an engine equipped
with the apparatus of the present invention.
Referring to the embodiment of the invention
disclosedin Figure 1 there is shown diagrammat
ically a portion of an internal combustion engine
equipped with a manifold riser I 0 connected with
a carbureting passage I2. A throttle valve I4 is
mounted on a throttle shaft I6 journalled in the
walls of the cabureting passage I2.
A conventional ignition timing unit is shown at
l8 and comprises the usual rotatable arm 28
driven by a system of gears connected with the
cam shaft of the engine and provided with a
contact point 24 which successively contacts with
the relatively stationary contacts 26 set in the
base member 22. Any suitable type of auto
matic spark advance such as the one illustrated
may'be employed, whereby the arm 28 is rotated
relative to its shaft 23 in accordance with engine
speed.
left-hand position, indicated at A in Figure 1, 15
to the position indicated at B, thereby advancing
the spark.
The operation when the throttle is approxi
mately one-fourth open is as follows. The cam
44 has rotated the lever 42 in the counterclock
wise direction about the pivot 43 to the position
indicated in dotted lines in Figure 1, moving piston
38 to the left by means of the rod 40 connected
with the lever 42. The partial vacuum existing
in the manifold riser I0 is transmitted to the
cylinder 28 by the duct 48 and moves the cylinder
28 to the left, rotating the arm 32 in the counter
clockwise direction to the position indicated at C
in Figure 1. The spark is then fully advanced.
The operation when the throttle is wide open 30
is as follows.
The vacuum in the manifold riser
is substantially at atmospheric, and the spring
46 has moved the cylinder 28 to the right, thereby
rotating the arm 32 in the clockwise direction to
retard the spark to the position indicated at B in
Figure 1.
It will be noted that when the engine. is not
running and the throttle valve I4 is closed, the
In the present invention, the spark, in addition . arm 32 is at the position indicated at A in Fig
to ‘being advanced and retarded by the automatic ure 1, wherein it abuts the stop member 36. The 40
spark is then fully retarded, which is desirable
spark advance, is advanced and retarded by ro
tating the base member 22 in a manner now to be
described. A floating cylinder 28 is slidably
mounted upon any suitable support 28 and is
45 operatively connected with the base member 22
by means of a rod 39 and an arm 32 which is
?xed to the base member .22 and yieldingly urged
toward the retarded position by a spring 34 which
holds the arm 32 against a stop member 36 under
certain operating conditions.
A piston 38 within the cylinder 28 is operably
connected with the throttle valve I4 through a
rod 451 which is pivoted to the free end of a lever
42 the other end being pivoted to a ?xed point 43
on the carburetor. The lever 42 is operated by
means of a cam 44 ?xed to the throttle shaft i5
and actuated in consonance with throttle move
ments by means of the usual throttle lever 45.
60 The cam 44 is so proportioned that it moves the
lever 42 rapidly when the throttle‘ valve I5 starts
to open, so that the full extent of travel is im
parted to the lever 42 by the time the throttle
valve I4 is about one-fourth open, after which
65 no further movement is imparted to the lever.
A spring 4'! connected to the lever 42 holds the
edge of the lever in contact with the surface of
the cam 44.
The piston 38 is yieldingly urged toward one end
of the cylinder 28 by a spring 46, and the cylinder
28 is subjected to the subatmospheric pressure or
vacuum existing in the manifold riser I8 by means
of a ?exible duct 43 communicating therewith.
The effect of the vacuum in the cylinder 23 is to
75 draw the cylinder to the left relative to the piston
when the engine is to be cranked.
As soon as the
engine has started and is operating at idling speed
with the throttle valve I4 closed, the vacuum in
the manifold riser Iii will urge the cylinder 28 to 45
the left, advancing the spark to the position B to
give satisfactory operation of the engine at idling
speed. When the throttle valve is progressively
opened and the engine is speeded up, the spark is
automatically advanced to the position repre
sented at C. As the engine is forced to carry an
increased load, the spark is automatically re
tarded back to the position B to prevent the en
gine from knocking.
In Figure 2, the curve A shows the relation be 55
tween the time of ignition and the speed of the
engine where only the conventional spark advance
device is employed. In this curve it will be noted
that the spark is advanced as the speed of the
engine is increased until a certain point, repre 60
sented by the numeral 54, is reached. From this
point an increase in speed of the engine will not
effect any change in the degree of spark advance.
The curve 13 represents the variation in the
spark advance where the instant invention is em
ployed as above described. It will be noted that
when the engine is being operated at extremely
low speeds, such as would be produced in crank
ing, the spark is retarded more than in the con
ventional device, as is indicated at 56 on curve B. 70
As the speed of the engine is increased, the spark
advances rapidly until a maximum point 58 is
reached, from which point the spark is retarded
slowly as the vacuum in the manifold drops due
to the opening of the throttle valve beyond a pre
3
2,109,103
determined point or approximately one-fourth
full open position and at high speeds the curve B
will meet the curve A.
The instant invention thus provides a greater
effective range of operation, together with greater
?exibility and e?iciency than can be obtained by
the conventional devices.
While a preferred embodiment of thisinven
tion has been shown and described in detail, it is
10 not my intention to limit the scope of the inven
tion to the arrangement shown nor otherwise
than by the terms of the appended claims.
I claim:
1. An internal combustion engine having an
15 ignition system including a distributor, a car
buretor having a throttle valve, a source of suc
tion posterior to said throttle valve, means con~
necting said distributor and carburetor and com
prising a cylinder operably connected with said
and retard the time of ignition, means including
a ?oating cylinder operably connected to one of
said relatively movable members and a piston
slidably mounted in the ?oating cylinder oper
ably connected to the throttle valve to advance
and retard the time of ignition, yielding means
urging the cylinder in the direction to retard
the time of ignition, and connecting means be
tween the source of suction and the cylinder.
6. An internal combustion engine having a 10
carburetor including a source of differential ?uid
pressure and a throttle valve, an ignition system
including a, distributor to advance and retard
the spark, centrifugally actuated means to ad
vance and retard the spark, auxiliary means in 15
cluding a floating cylinder operably connected
to the distributor and a piston operably con
nected to the throttle valve and slidable in the
cylinder to advance and retard the spark, and
20 distributor, a piston slidably mounted within the
connecting means between the source of suction 20
40 toward one extreme position.
tard the time of ignition, means including a 40
and the cylinder.
cylinder, yielding means urging the cylinder to
7. In an internal combustion engine a carbu
ward one extreme position, connecting means be
tween the cylinder and the source of suction, and retor including a source of differential ?uid pres
connecting means including a throttle actuated sure and a throttle valve, a cam ?xed to the
25
25 cam between said piston and said throttle valve. . throttle valve, an ignition system including a
2. An internal combustion engine having an distributor to advance and retard the spark,
ignition system including a distributor having means including a ?oating cylinder operably con
two members movable relative to each other to nected to the distributor and a piston slidable in
the cylinder and operate-d by said cam to ad
advance and retard the spark, a carburetor hav
vance and retard the spark, connecting means 30
30 ing a throttle valve, a source of suction posterior
between the source of suction and the cylinder,
to said throttle valve, means connecting said dis
and yielding means urging the cylinder to one
tributor and carburetor and comprising a cyl
extreme position to retard the spark.
inder operably connected with one of said mem
8. In an ignition control system for an internal
bers, a piston slidably mounted within the cyl
combustion engine having a carburetor forming a 35
inder,
yielding
means
urging
the
piston
toward
35
one extreme position, connecting means between source of suction and equipped with a throttle
valve, a cam ?xed to the throttle valve, an igni
the cylinder and the source of suction, connect
ing means between said piston and said throttle tion system including a plurality of relatively
valve, and yielding means urging said cylinder movable members operable to advance and re
-
3. An internal combustion engine having an
ignition system including a distributor having
two members movable relative to each other to
advance and retard the spark, a carburetor hav
45 ing a throttle valve, a source of suction posterior
to said throttle valve, means connecting said dis
tributor and carburetor and comprising a cyl
inder operably connected with one of said mem
bers, a piston slidably mounted within the cyl
inder, connecting means between the cylinder and
50
the source of suction, connecting means between
the piston and the throttle valve, and yielding
means urging the cylinder toward one extreme
position, said connecting means being operable
55 to regulate the time of ignition in accordance
with the speed of the engine and pressure exist
ing in the source of suction.
4. In an ignition control system for an internal
combustion engine having a carburetor forming
60 a source of suction and equipped with a throttle
valve, an ignition system including a plurality of
relatively movable members operable to advance
and retard the time of ignition, means including
a ?oating cylinder and a piston operably con
65 nected to the throttle valve to control one of
said relatively movable members, and connecting
means between the source of suction and the cyl
inder.
5. An ignition control system for an internal
combustion engine having a carburetor forming a
70 source of suction and equipped with a throttle
valve, an ignition system including a plurality of
relatively movable members operable to advance
?oating cylinder operably connected to one of
said relatively movable members and a piston
slidably mounted in the ?oating cylinder and as
sociated with the throttle valve and actuated by
said cam to advance and retard the time of igni 45
tion, yielding means urging the cylinder in the
direction to retard the time of ignition, and con
necting means between the source of suction and
the cylinder.
9. An internal combustion engine having an 50
ignition system, a carbureting system, a throttle
valve controlling the carburetor, a member mov
able in accordance with throttle position, a source
of suction associated with the carburetion sys
tem, and means including a movable cylinder 55
and a piston operably connected to said mem
ber and controlled jointly by throttle position and
suction interconnecting the ignition and carburet- '
ing systems for automatically advancing the time
of ignition as the engine is speeded up and re 60
tarding the ignition as the pressure in said source
of suction rises to atmospheric.
10. In an internal combustion engine, an igni
tion system including a control member movable
to advance and retard the spark, a carburetor 65
comprising a throttle, a member movable in ac
cordance with movements of the throttle, and
a connection between said movable member and
said control member comprising a movable cyl
inder and piston the relative positions of which 70
are variable in accordance with the degree of
suction posterior to the throttle.
DON COLE.
Документ
Категория
Без категории
Просмотров
0
Размер файла
566 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа